You don't need to change the bedding, if you use a larger particle such as oats, then you can just sieve the worms waste out when you need too - I have several hundred in a 57 liter tub and sieve it out every few months.
Sofoula, there are a couple of pics of my set up on my fb page, if you feel like having a look
My wealworms are in a big round take away food tub (about 1/2 full of wheat bran), not progressed to a larger worm farm container yet. (Think I have about 300 worms in it, this is 1/2 my second batch, I took the trouble of buying a 100g tub and immediately separating and counting the worms (100g == 650 medium worms) and I froze 1/2 of them.
I find that the carrots (that I cut into long chunks) start to go mouldy in about 3 days and since I think mouldy carrots killed a lot of my first batch of worms, I remove the carrots when they get wet/slimy to touch now.
I'm keeping my worms at room temperature as my refrigerator is too cold for them, runs at < 7 C and I am not inclined to adjust the refrigerator's thermostat to enable me keep worms in the fridge (will mean food will spoil quicker and my wife does not want worms living in the fridge).
I find that the bedding gets smelly after about a week - 10 days and Lizzy doesn't like the smell of the worms when the bedding is smelly. She's got to be really hungry to accept smelly worms. I've had this batch with minimal losses at room temperature since the 4th.
I found I had a lot of cannibalism going on with my first batch of worms, they are like little vampires - sucked a lot of their mates dry. Only lost a few this way this time - nice carrot pieces seem to keep them happy.
So fsr I've fished out 12 pupae.
When my beatles emerge, I'll put them into a separate tub with some bedding (a thin layer) to lay their eggs in that I'll screen to remove all the fine wheat meal from - hoping that'll make it easier to extract the eggs, Else I'll just let the eggs hatch in that tub.
I've only one lizard to keep happy, my little house lizard Lizzy the Skink, and she'll never want more than 3 or 4 worms 2 or 3 times a week, she catches a lot of her own food under the house and inside the house and likes foraging on the kitchen floor for little bits and pieces. And I often put food treats on a take away lid for her to find (bits of diced BBQ chicken meat, bits of roast lamb, the occasional small seedless grape (cut in half), the occasional raw pea).
The mealworms and the occasional medium live cricket are treats and I am using them as a means of building my relationship with Lizzy (and to encourage her to stick around). So far so good and I've made a lot of progress with her, she now accepts food treats from my fingers, and allows me to stroke her and even hand surfs sometimes.
I've also plans on using mealworms as fishbait. Not sure how that'll go, but I suspect mullet, whiting, bream and yellowtail will like them, and I might find them OK for freshwater lake and river fishing species (bass and yellowbelly) ,so any surplus of mealworms wont go to waste. And they seem to freeze pretty good too.